Department of Ophthalmology, Yonge-Eglinton Laser Center, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
Cornea. 2014 Feb;33(2):131-6. doi: 10.1097/ICO.0000000000000044.
The aim of this study was to report the outcomes of corneal collagen crosslinking (CXL) after previous radial keratotomy (RK) in patients with decreasing visual acuity and/or diurnal visual fluctuations.
The charts of all patients who had undergone CXL because of a worsening corrected distance visual acuity (CDVA) and/or diurnal visual fluctuations after RK were reviewed retrospectively. Uncorrected distance visual acuity, CDVA, manifest refraction, and corneal topography were recorded preoperatively and at 1, 3, 6, and 12 months after the procedure.
Nine eyes of 6 patients that had undergone an RK 15 to 23 years before the CXL were included in the study. In 5 patients (8 out of 9 eyes), discontinuation of diurnal visual fluctuation was reported between 6 and 12 months after the CXL. The mean uncorrected distance visual acuities pre and 12 months after the CXL were 0.7 logarithm of the minimum angle of resolution (logMAR) and 0.6 logMAR, respectively (P = 0.3). The mean CDVAs pre and 12 months after the CXL were 0.2 logMAR and 0.1 logMAR (P = 0.5), respectively. The mean average keratometry pre and 12 months after the CXL were 40.1 and 39.1 diopters (P = 0.06), respectively. The mean corneal astigmatism values pre and 12 months after the CXL were 2.3 and 1.9 diopters (P = 0.06), respectively. The mean manifest refraction spherical equivalents (MRSEs) before and 12 months after the CXL were +1.4 and +2.5 (P = 0.1), respectively.
CXL is a safe and effective method to restore corneal stability in eyes with a history of RK. However, some of the effect that was achieved at the 6-month visit was blunted at the 12-month visit. Therefore, a longer follow-up is necessary to validate these findings.
本研究旨在报告先前行放射状角膜切开术（RK）后行角膜胶原交联（CXL）的患者，因视力下降和/或昼夜视觉波动而行 CXL 的结果。
回顾性分析所有因 RK 后矫正视力（CDVA）下降和/或昼夜视觉波动而行 CXL 的患者的图表。记录术前和术后 1、3、6 和 12 个月的未矫正距离视力（UDVA）、CDVA、主觉验光和角膜地形图。
本研究共纳入 6 例 9 只眼，RK 术后 15 至 23 年行 CXL。在 5 例患者（9 只眼中的 8 只）中，CXL 后 6 至 12 个月报告昼夜视觉波动停止。CXL 前后的平均 UDVA 分别为 0.7 最小分辨角对数视力（logMAR）和 0.6 logMAR（P = 0.3）。CXL 前后的平均 CDVA 分别为 0.2 logMAR 和 0.1 logMAR（P = 0.5）。CXL 前后的平均平均角膜曲率分别为 40.1 和 39.1 屈光度（P = 0.06）。CXL 前后的平均角膜散光值分别为 2.3 和 1.9 屈光度（P = 0.06）。CXL 前后的平均主觉折射等效球镜（MRSE）分别为+1.4 和+2.5（P = 0.1）。
CXL 是一种安全有效的方法，可恢复 RK 后角膜稳定性。然而，6 个月时观察到的部分效果在 12 个月时减弱。因此，需要更长的随访时间来验证这些发现。
